Watch your language (body language, that is).

Leaning forward shows that you're interested. Look people in the eyes when you're talking to them. A clear, direct gaze portrays candor and sincerity. No slouching. Stroking your neck and throat involuntarily makes you look uneasy. Pressing your fingertips together in a steeple formation is also a simple sign of self-confidence, but don't overdo it. Be careful about folding your arms across your chest it can come off as a defensive posture.